#!/bin/sh
#
# CDDL HEADER START
#
# The contents of this file are subject to the terms of the
# Common Development and Distribution License (the "License").
# You may not use this file except in compliance with the License.
#
# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
# or http://www.opensolaris.org/os/licensing.
# See the License for the specific language governing permissions
# and limitations under the License.
#
# When distributing Covered Code, include this CDDL HEADER in each
# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
# If applicable, add the following below this CDDL HEADER, with the
# fields enclosed by brackets "[]" replaced with your own identifying
# information: Portions Copyright [yyyy] [name of copyright owner]
#
# CDDL HEADER END
#
#
# Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
# Use is subject to license terms.
#

#
# This is third phase of TCP/IP startup/configuration.  This script
# runs after the NIS startup script.  We run things here that may
# depend on NIS maps.
#

. /lib/svc/share/smf_include.sh
. /lib/svc/share/net_include.sh

NWAM_FMRI="svc:/network/physical:nwam"
AWK=/usr/bin/gawk

case "$1" in
'start')
	#
	# In a shared-IP zone we need this service to be up, but all of the
	# work it tries to do is irrelevant (and will actually lead to the
	# service failing if we try to do it), so just bail out. 
	# In the global zone and exclusive-IP zones we proceed.
	#
	smf_configure_ip || exit $SMF_EXIT_OK

	#
	# If nwam is enabled, the nwam service will handle the tasks performed
	# by this service, so just bail out.
	#
	service_is_enabled $NWAM_FMRI && exit $SMF_EXIT_OK
	;; # fall through -- rest of script is the initialization code

'stop')
	exit $SMF_EXIT_OK
	;;

*)
	echo "Usage: $0 { start | stop }"
	exit 1
	;;
esac

interface=$2

# If boot variables are not set, set variables we use
[ -z "$_INIT_UTS_NODENAME" ] && _INIT_UTS_NODENAME=`/usr/bin/uname -n`

#
# This function takes two file names and the file mode as input. The two
# files are compared for differences (using cmp(1)) and if different, the
# second file is over written with the first. A chmod is done with the file
# mode passed in. If the files are equal, the first file passed
# in (the /tmp file) is deleted.
#
mv_file ()
{
	/usr/bin/cmp -s $1 $2
	if [ $? -eq 1 ]; then
		/usr/bin/mv $1 $2
		#
		# The umask during boot is configurable, which requires
		# explicit setting of file permission modes when we
		# create files.
		#
		/usr/bin/chmod $3 $2
	else
		/usr/bin/rm $1
	fi
}

#
# This function takes a DHCP parameter (as defined in /etc/dhcp/inittab)
# and returns the value for that parameter returned by the DHCP server.
# If the global 'interface' is defined, it will request the value learned
# on that interface, else it will request the value learned on the primary
# interface.
#
get_dhcp_var ()
{
	if [ -n "$interface" ]; then
		/sbin/dhcpinfo -i $interface $1
	else
		/sbin/dhcpinfo $1
	fi
}

#
# This function returns true if the string "# Added by DHCP$" occurs in
# the passed-in file, false otherwise.
#
dhcp_edits ()
{
	/usr/bin/grep '# Added by DHCP$' $1 >/dev/null 2>&1
	return $?
}

#
# update_resolv()
# Go through /etc/resolv.conf and replace any existing domain or
# nameserver entries with new ones derived from DHCP.  Note that
# it is important to preserve order of domain entries vs. search
# entries; the search entries are reserved for administrator
# customization and if placed after the domain entry will override
# it.  See resolv.conf(5).
#
# The first arg should be the dns servers string, the second
# should be the dns domain.
#
update_resolv ()
{
	dnsservers=$1
	dnsdomain=$2

	if [ ! -f /etc/resolv.conf ]; then
		/usr/bin/touch /etc/resolv.conf
	fi
	export dnsservers dnsdomain
	${AWK} </etc/resolv.conf >/tmp/resolv.conf.$$ '
		function writedomain() {
			if (updated == 0) {
			    	# Use only first domain, not a search list
			    	split(ENVIRON["dnsdomain"], d)
				if(length(d[1]) != 0)
					printf("domain %s\n", d[1])
			}
			++updated
		}
		$1 == "domain" { writedomain(); next }
		$1 != "nameserver" { print $0 }
		END {
			writedomain()
			n = split(ENVIRON["dnsservers"], s)
			for (i = 1; i <= n; ++i)
				printf("nameserver %s\n", s[i])
		}'
	unset dnsservers dnsdomain
	mv_file /tmp/resolv.conf.$$ /etc/resolv.conf 644
}

#
# update_nss()
# This routine takes as a parameter, the name of the respective policy 
# to change in the nsswitch.conf (hosts or ipnodes) to update with dns.
#
update_nss ()
{
	policy=$1;
	# Add dns to the nsswitch file, if it isn't already there.
	${AWK} ' $1 ~ /^'${policy}':/ {
		n = split($0, a);
		newl = a[1];
		if ($0 !~ /dns/) {
			printf("#%s # Commented out by DHCP\n", $0);
			updated = 0;
			for (i = 2; i <= n; i++) {
				if (updated == 0 && index(a[i], "[") == 1) {
					newl = newl" dns";
					updated++;
				}
				newl = newl" "a[i];
			}
			if (updated == 0) {
				newl = newl" dns";
				updated++;
			}
			if (updated != 0)
				newl = newl" # Added by DHCP";
			else
				newl = $0;
			printf("%s\n", newl);
		} else
			printf("%s\n", $0);
	} $1 !~ /^'${policy}':/ { printf("%s\n", $0); }' /etc/nsswitch.conf \
	    >/tmp/nsswitch.conf.$$

	mv_file /tmp/nsswitch.conf.$$ /etc/nsswitch.conf 644
}

#
# Remove any lines with the "# Added by DHCP" tag from /etc/nsswitch.conf;
# also uncomment hosts and ipnodes entries which were previously commented
# out by this script.
#
cleanup_nss ()
{
	/usr/bin/sed \
	    -e '/# Added by DHCP$/d' \
	    -e 's/^\(#hosts:\)\(.*[^#]\)\(#.*\)$/hosts: \2/' \
	    -e 's/^\(#ipnodes:\)\(.*[^#]\)\(#.*\)$/ipnodes: \2/' \
	    /etc/nsswitch.conf >/tmp/nsswitch.conf.$$

	mv_file /tmp/nsswitch.conf.$$ /etc/nsswitch.conf 644
}

#
# Remove any lines with the "# Added by DHCP" tag from /etc/inet/hosts.
#
cleanup_hosts ()
{
	${AWK} '{
		if (index($0, "# Added by DHCP") == 0 ||
		    $1 == "127.0.0.1" || $1 == "::1") {
			print $0
		}
	}' /etc/inet/hosts > /tmp/hosts.$$
	mv_file /tmp/hosts.$$ /etc/inet/hosts 444
}

#
# If our network configuration strategy is DHCP, check for DNS
# configuration parameters obtained from the DHCP server.
#
# Script execution starts here.
#
smf_netstrategy

if [ "$_INIT_NET_STRATEGY" = "dhcp" ]; then
	dnsservers=`get_dhcp_var DNSserv`
	dnsdomain=`get_dhcp_var DNSdmain`
elif smf_is_nonglobalzone; then
	str="$(/sbin/netstrategy)"
	if [ $? -eq 0 ]; then
		_INIT_NET_IF="$(echo "${str}"|${AWK} '{print $2}')"
		_INIT_NET_STRATEGY="$(echo "${str}"|${AWK} '{print $3}')"
		dnsservers=`get_dhcp_var DNSserv`
		dnsdomain=`get_dhcp_var DNSdmain`
	else
		dnsservers=""
		dnsdomain=""
	fi
else
	dnsservers=""
	dnsdomain=""
fi

if [ -n "$dnsservers" ]; then
	#
	# add settings retrieved from dhcp server to /etc/resolv.conf
	#
	update_resolv "$dnsservers" "$dnsdomain"

	#
	# Add dns to the nsswitch file, if it isn't already there.
	#
	update_nss hosts
	update_nss ipnodes

elif dhcp_edits /etc/nsswitch.conf; then
	# If we added DNS to the hosts and ipnodes
	# policy in the nsswitch, remove it.
	cleanup_nss
fi

if dhcp_edits /etc/inet/hosts; then
	# Clean up any old DHCP-added entries
	# (except loopback) in the hosts file.
	cleanup_hosts
fi

